A fleet that launches itself

What has to be in user-data for a machine to finish a job with nobody watching.

A benchmarking campaign across hundreds of instance types cannot have a person watching each one. Each instance boots from a user-data script that installs the toolchain, runs the benchmark, uploads the results and terminates itself. The first run where every report came back clean was the milestone.

The interesting failures came before it. A machine that finishes and does not terminate keeps billing until someone notices.

flowchart LR
  L[Launch] --> I[cloud-init: toolchain] --> R[Run benchmark] --> U[Upload results] --> T[Terminate]
  W[Watchdog] -.-> T

Takeaway

Termination is the first thing the script guarantees, not the last.

Client engagement, 2021 to 2026. Names, identifiers and internals are generalised.